Just make sure you buy premium quality brands; Cheap fiberglass is not that strong and will crack in cold weather. Fiberglass is also highly resistant to mold, decay, and rust, giving it some power advantages over regular steel, aluminum, and wood. When it comes to a security door, you can get away with any of them. The main difference is aesthetics and not durability.Interior security door: ClassificationThe classification of security doors is based on burglary resistance, that is, a period of time during which the door can maintain its integrity during a physical and chemical attack on the door. Let's look at the classification of security doors in more detail so you can choose. • CLASS I - this door can be opened using physical force and hand tools (wrecking bar or hacking iron). It only offers basic protection against burglary. The thickness of the door leaf is approximately 20 mm. • CLASS II – opening this door may require the use of electric saws and electric drilling tools. The thickness of the door leaf does not exceed 80 mm. • CLASS III – to open this door, powerful drilling tools with a power capacity of approximately 2000 W must be used. The thickness of a steel door leaf is not less than 120